The objective of the Pharmacology Core is to enable the projects in this Center to develop new classes of host-targeting antiviral therapeutics for the Priority viruses. The overall goal of this core is to provide the infrastructure that will enable compounds for each project to advance in pre-clinical development. This core will establish capabilities and a Center-focused collection of expertise and advisors, which are not available on the Stanford University campus or commercially. To achieve the above goals, the pharmacology core will accomplish the following specific aims, which are to provide: (i) Medicinal chemistry capabilities to produce compound series required for: characterization of lead compounds, their structure-activity-relationships, design and synthesis of pro-drugs, and analysis of drug metabolites. (ii) In vitro characterization of drug metabolism in murine and human systems. (iii) In vivo analysis of drug metabolism in conventional mice and in mice with humanized livers. (iv) In vivo analysis of drug efficacy in mice with humanized livers. (v) Biostatistical support for analysis of all data produced by the Program's projects and by the Pharmacology Core.